1. Field of the Invention
The present invention relates to a self-drilling rock anchor for use in mine and tunnel constructions, and in particular to a self-drilling chemical connection anchor. The rock anchor includes an anchor tube provided with a drill head at its first end. At its second, free end, the anchor tube is provided with a profile. On the second, free end, the rock anchor is provided with a releasably connectable therewith adapter having engagement or intervention means that cooperate with a rotatable chuck of a usable drilling tool.
2. Description of the Prior Art
Self-drilling rock anchors, in particular chemical connection anchors and suitable drilling tools with rotatable chucks, and their use in mine and tunnel constructions are well known since long ago. The rock anchors serve primarily for stabilizing walls and hollow spaces in mines, tunnels, galleries, and the like. When hollow spaces are formed, mechanical properties and, in particular, the bearing capacity of stratum is reduced. These stratum are anchored to lying further, undamaged stratum with rock anchors, e.g., chemical connection anchors, and are, thus, secured thereto.
The anchor tube of a rock anchor functions, on one hand, as a drill rod and, on the other hand, when formed as a chemical connection anchor, as a receptacle for a to-be-pressed out mass. A drill head is provided at a first, facing in the setting direction, end of the anchor tube. The second end of the anchor tube is inserted into a chuck of a usable drilling tool with which the anchor tube is set into a constructional component.
Austrian Patent AT-396 390 B discloses a self-drilling rock anchor which is connected to the drilling tool with a coupling sleeve. The drawback of this solution consists in that the free end of the rock anchor needs to be adapted to the shape of the receptacle in the coupling sleeve.
German Publication DE 3610 880 A1 discloses a drill rod that has a sleeve-shaped receptacle with an inner thread for a further drill rod. The further drill rod has a section with an outer thread engageable with the inner thread of the sleeve-shaped receptacle. The drawback of this solution consists in that with the use of this connection technology, the chuck of a drilling tool should be screwed off the drilling rod set in the constructional component with a special tool after the drilling process ended.
Accordingly, an object of the present invention is to provide a self-drilling rock anchor that can be easily set in and which would provide for rapid mounting of the rock anchor in and dismounting of a usable drilling tool.
Another object of the present invention is to provide a rock anchor that can be cost-effectively produced.